Mechanical Behavior of Earthcrete Building Units Embedded with Glass Bottles

Abstract

Glass is endlessly recyclable, yet only a fraction of container glass is recycled globally, while countries such as Brazil simultaneously face a severe shortage of affordable housing. In response, low-income communities have begun embedding used glass bottles in earthen mortars to construct walls. However, scientific investigation of glass bottles as structural components in earthcrete blocks is virtually absent from the literature. This thesis investigates the influence of different bottle configurations on the mechanical behavior of earthcrete building units embedded with long-neck beer bottles, using a combined numerical and experimental approach. Finite element models were developed in Abaqus using the Concrete Damage Plasticity model, calibrated on experimental data from earlier research on single-bottle blocks. A parametric study of cubic blocks (240 mm) was performed in which the number of vertically oriented bottles (0–9) and the earthcrete cover (2–6 cm) were varied. Based on these simulations, three configurations were fabricated and tested under uniaxial compression. The experiments proved highly repeatable: the plain block reached a mean capacity of 401 kN, whereas the four- and five-bottle blocks reached 330 kN and 349 kN respectively, corresponding to a capacity reduction of 18 and 13% and a distinctly more brittle post-peak response. The calibrated numerical model over-predicted the experimental capacities by 42–125% and incorrectly predicted that capacity increases with bottle
count. Recalibration improved the agreement but remains a fit rather than a validation. A Eurocode 6 case study demonstrates that a two- to three-storey residential building on bottle-embedded walls satisfies the ultimate limit state verification. It is concluded that embedded glass bottles act not as reinforcement but as functional voids: for a modest loss of compressive capacity,
they reduce material use and divert waste glass from disposal, making their value primarily economic and environmental rather than structural.